1. Field of the Invention
The present invention relates to a washing and drying machine, and, more particularly, to a washing and drying machine that is capable of performing heat exchange between outside air introduced into a cabinet and the circumferential surface of a tub so as to condense air used to dry laundry, thereby minimizing flow resistance, improving drying efficiency, and reducing maintenance costs.
2. Description of the Related Art
Generally, a washing machine is a machine that is capable of removing pollutants from clothes or bedclothes (hereinafter, referred to as “laundry”) with detergent-dissolved water or pure water (hereinafter, referred to as “washing water”). Recently, a large number of washing machines have incorporated a drying unit for drying the laundry, and therefore, each washing machine has a drying function.
FIG. 1 is a longitudinal sectional view illustrating the interior of a conventional washing and drying machine.
As shown in FIG. 1, the conventional washing and drying machine comprises: a cabinet 2 forming the exterior of the washing machine; a tub 10 mounted in the cabinet 2 for receiving washing water; a drum 20 rotatably disposed in the tub 10 for receiving laundry 1; and a motor 30 for rotating the drum 20.
At the front surface of the cabinet 2 is formed a laundry inlet/outlet hole 3, through which the laundry 1 is put into the drum 20 and removed from the drum 20. The laundry inlet/outlet hole 3 is opened or closed by a door 4.
The tub 10 is mounted in the cabinet while being suspended by springs 5 connected between the upper end of the cabinet 2 and the tub 10. Also, the tub 10 is supported by a damper 6 disposed at the lower end of the cabinet 2 such that shock applied to the tub 10 is effectively absorbed by the damper 6.
To the tub 10 is connected a water supply unit 7 for supplying washing water into the tub 10 from the outside of the washing machine. To the tub 10 is also connected a drainage unit 8 for draining the washing water out of the tub 10.
At the center part of the front surface of the tub 10 is formed a tub opening hole 11, through which the laundry 1 and air are introduced into or discharged from the tub 10. To the front surface of the tub 10 is attached a gasket 9, which comes into tight contact with the door 4, when the door 4 is closed, for preventing the laundry 1, the washing water, and the air from being discharged from a gap between the tub 10 and the door 4.
At the inner bottom surface of the tub 10 is mounted a washing heater 13 for heating the washing water such that the laundry can be washed with hot water. At the inner bottom surface of the tub 10 is also mounted a washing temperature sensor (not shown) for detecting the temperature of the washing water.
At the front surface of the drum 20 is formed a drum opening hole 21, through which the laundry 1 and air are introduced into or discharged from the drum 20. At the circumferential surface of the drum 20 are formed a plurality of through-holes 22, through which washing water and air are introduced into or discharged from the drum 20.
To inner wall of the drum 20 are attached lifters 23, by which the laundry 1 is lifted and then falls.
The washing and drying machine further comprises: a drying duct 40, having a circulating fan 41 and a drying heater 42, for supplying hot air into the drum 20; and a condenser 43 for condensing wet air generated when the drum 20 is dried and guiding the condensed air to the drying duct 40.
In the drying duct 40 is mounted a fan motor 44 for rotating the circulating fan 41. The outlet end of the drying duct 40 is fixedly inserted into or fitted onto a drying duct connection member 12, which is formed at the gasket 9.
The condenser 43 comprises: a condensing duct 45 connected to the rear part of the tub 10 for allowing air to pass therethrough; and a cooling water supply unit 46 for supplying cooling water into the condensing duct 45 such that the air passing through the condensing duct 45 is cooled by the cooling water and thus condensed.
The inlet end of the condensing duct 45 is diagonally opposite to the outlet end of the drying duct 40 such that dry air introduced into the tub 10 from the drying duct 40 is uniformly circulated in the tub 10, and is then discharged into the condensing duct 45.
Specifically, the outlet end of the drying duct 40 is connected to the front upper part of the tub 10 while the inlet end of the condensing duct 45 is connected to the rear lower part of the tub 10.
In the condensing duct 45 is mounted a condenser temperature sensor 47 for detecting the temperature of air cooled by the cooling water.
The operation of the conventional washing and drying machine with the above-stated construction will now be described.
When a user puts the laundry 1 into the drum 20, closes the door 4, and operates the washing machine, washing water is introduced into the cabinet 2 through the water supply unit 7.
The introduced washing water is supplied into the tub 10, and is then introduced into the drum 20 through the drum opening hole 21 or the through-holes 22 such that the laundry 1 is wetted by the washing water.
As the motor 30 is operated, the drum 20 is rotated, and as a result, pollutants are separated from the laundry 1 by the washing water.
After the above-described washing process is completed, the pollutant contaminated washing water is drained out of the tub 10 through the drainage unit 8. Subsequently, a rinsing process for rinsing bubbles from the laundry 1 is performed several times.
After the rinsing processes are completed, a water removing or spinning process is performed to remove moisture from the laundry 1 by centrifugal force.
After the water removal process is completed, a drying process for drying the laundry 1 is performed. The drum 20 is rotated by the motor 30, and the circulating fan 41 and the drying heater 42 are turned on. Also, the cooling water is supplied into the condensing duct 45 through the cooling water supply unit 46.
As the circulating fan 41 is rotated, low-temperature and high-humidity air in the drum 20 is introduced into the condensing duct 45 through the through-holes 22 of the drum 20 and the tub 10.
At this time, the cooling water supplied through the cooling water supply unit 46 falls into the condensing duct 45, and the moisture in the air introduced into the condensing duct 45 is condensed by the cooling water. As a result, the air is dried.
After the air passes through the condensing duct 45, the air passes through the drying duct 40. At this time, the air is heated by the heater 42, and as a result, the air is changed into hot air. The hot air is blown to the front surface of the drum 20 through the outlet end of the drying duct 40.
The laundry 1 is dried in the drum 20 by the blown hot air, and as a result, the hot air is changed into low-temperature and high-humidity air, which flows into the condensing duct 45.
In the conventional washing and drying machine with the above-state construction, however, it is necessary that the condensing duct 45 be relatively long so as to sufficiently condense moisture contained in the air passing through the condensing duct 45. As a result, flow resistance is large, and the capacities of the tub 10 and the drum 20 are relatively decreased. Furthermore, a great amount of cooling water is consumed to cool the condensing duct 45, and therefore, the maintenance costs of the conventional washing and drying machine are increased.